U.S. patent number 4,537,193 [Application Number 06/437,288] was granted by the patent office on 1985-08-27 for laser endocoagulator apparatus.
This patent grant is currently assigned to HGM, Inc.. Invention is credited to Howard M. C. Tanner.
United States Patent |
4,537,193 |
Tanner |
August 27, 1985 |
Laser endocoagulator apparatus
Abstract
A disposable laser endocoagulator apparatus for ophthalmic
surgery or the like. The apparatus includes an elongated, generally
pencil-like handtool which has a stainless steel probe positioned
at the leading end of the handtool. An optical fiber is inserted
through a bore in the handtool such that the optical fiber
terminates at the distal end of the probe. The optical fiber is
attached to a connector which includes a plastic body, the plastic
body having a small metal plug inserted into it. The metal plug is
constructed of stainless steel so as to be capable of being
machined with great precision such that the optical fiber carried
by the plug can be accurately positioned and aligned with respect
to the laser beam output by a conventional argon ion type
laser.
Inventors: |
Tanner; Howard M. C. (Salt Lake
City, UT) |
Assignee: |
HGM, Inc. (Salt Lake City,
UT)
|
Family
ID: |
23735834 |
Appl.
No.: |
06/437,288 |
Filed: |
October 28, 1982 |
Current U.S.
Class: |
606/4; 385/84;
606/15; D24/144 |
Current CPC
Class: |
G02B
6/4296 (20130101); A61B 18/24 (20130101) |
Current International
Class: |
A61B
18/20 (20060101); A61B 18/24 (20060101); G02B
6/42 (20060101); A61B 017/36 (); A61N 005/00 () |
Field of
Search: |
;128/303.1,395-398
;219/121L,121LP,121LQ,121LR ;350/96.20 ;372/108 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
2740969 |
|
Mar 1979 |
|
DE |
|
2828322 |
|
Jan 1980 |
|
DE |
|
2479485 |
|
Oct 1981 |
|
FR |
|
Other References
Smith et al., "New Trends in CO.sub.2 Laser Micro. . . . ", SPIE,
vol. 236, 1980, pp. 173-182..
|
Primary Examiner: Cohen; Lee S.
Attorney, Agent or Firm: Olive; B. B.
Claims
What is claimed and desired to be secured by United States Letters
Patent is:
1. A disposable endocoagulator apparatus adapted for connection to
an argon laser having a female receptacle providing a laser output
suited to optical fiber transmission for ophthalmic surgery and
like procedures, comprising:
(a) an elongated, cylindrical-shaped handtool formed as a integral,
plastic molded structure having:
(i) a cylindrical, pencil-like body having a leading end and a
trailing end;
(ii) a tip portion formed integral with said body leading end and
tapered towards the leading end of said body;
(iii) a central bore extending through the length of said handtool
body and tip portion;
(iv) within said tip portion a first enlarged bore concentric with
said central bore for mounting a probe;
(v) within the trailing end of said body a second enlarged bore
concentric with said central bore for receiving a first optical
fiber sheath; and
(vi) within said body an annular shoulder surrounding and
concentric with said central bore and extending within said body
between said shoulder and said second enlarged bore a third
enlarged bore substantially equal in size to the size of said first
enlarged bore and concentric with said central bore for receiving a
second optical fiber sheath;
(b) a hollow, elongated, stainless steel tube forming a laser
probe, said probe having a minor portion of the length thereof
anchored in said tip portion first enlarged bore and having a major
portion of the length thereof extending outwardly from said tip
portion to a leading end, the axis of said probe being aligned with
the axis of said handtool;
(c) a fiber optics connector assembly comprising:
(i) an elongated, cylindrical-shaped, integral, plastic-molded body
member having a leading end and a trailing end and having a central
bore through the length thereof and a fourth enlarged bore at the
trailing end thereof concentric with said body member central bore,
said body member having a flat annular surface at the trailing end
thereof surrounding said body member fourth enlarged bore; and
(ii) a cylindrical, precisely-formed, male plug member having a
leading end and a trailing end and positioned at the trailing end
of and forming an integral connector structure with said body
member, said plug member having a cylindrical portion of reduced
diameter at its leading end and being secured to said body member
by said plug member leading end of reduced diameter being inserted
and secured in said body member fourth enlarged bore, the trailing
end of said plug member being tapered for guiding said male plug
member into said female receptacle, said plug member having a bore
aligned with and forming a continuation of the central bore of said
body member and at the trailing end of said plug member an inwardly
tapered recess around the plug member bore, the diameter and length
of said male plug member being adapted for precise alignment and
positioning within a mating argon laser female receptacle having an
output source oriented along an axis aligned with the axis of said
male plug member when inserted in said female receptacle, said flat
annular surface serving as a stop for controlling the depth of said
plug member in said receptacle; and
(d) a single, continuous length of optical fiber, said optical
fiber having:
(i) a leading portion extending from a leading polished end surface
positioned slightly outwardly from the leading end of said probe
and extending through said probe and handtool bore;
(ii) an intermediate portion extending from the trailing end of
said handtool to said connector assembly;
(iii) a trailing end portion extending through said connector
assembly body member central bore and said plug member bore and
terminating with a trailing end surface disposed slightly within
said plug member recess;
(iv) a first cladding sheath extending over said length of optical
fiber from a location slightly behind the leading polished end
thereof to a location within said plug member and forwardly of said
recess; and
(v) a second plastic sheath anchored in said connector assembly
body member central bore at one end and surrounding said optical
fiber and extending to and anchored in said second enlarged bore at
the trailing end of said handtool.
2. A disposable endocoagulator apparatus as claimed in claim 1
wherein said plug member is formed of a precision machined metal.
Description
BACKGROUND
1. The Field of the Invention
The present invention relates to laser apparatus used for purposes
of surgery and, more particularly, to a disposable laser
endocoagulator apparatus for ophthalmic surgery.
2. The Prior Art
The advent of the laser has opened new frontiers to many areas of
science and has revolutionized many procedures. One of the most
important of these new frontiers has been the application of laser
technology to various procedures in the field of medicine. Because
lasers can be focused onto very small areas, it is possible to be
very precise and to treat specific pathologies without affecting
surrounding tissue.
The first significant medical use of a laser occurred in 1965 when
doctors utilized a laser to repair a detached retina. The surgeons
were able to focus the laser into the interior portion of the
eyeball and "weld" the detached retina back into place. At the
point where the laser beam struck the retina, the light energy was
converted into heat energy which produced a coagulum. During the
next few weeks, this coagulum was converted to scar tissue which
anchored the retina in place. Since that time, the procedure has
been much improved and the utilization of lasers has become a
generally accepted method of repair in this type of abnormality.
Surgical laser apparatus has also been used to repair retinal tears
and abnormal blood vessels within the eye.
Notwithstanding the substantial advances in ophthalmic surgery
which have come about as a result of the improvements in laser
technology, the current state of the art leaves much to be desired.
For example, in the past it has been common practice to use xenon
lasers for purposes of ophthalmic surgery. The laser beam from a
xenon laser has a tendency to scatter to a certain degree, thus
losing some of its intensity and precision. Because of this
tendency, the tip of the optical fiber through which the laser beam
passes must almost be in contact with the eye tissue which is being
treated. Since ophthalmic surgery is typically conducted in the
dark so that only the area of the eye on which the surgery is
occurring is illuminated, this increases the possibility of causing
additional damage to the eye because the surgeon, in attempting to
place the tip of the optical fiber so that it is almost in contact
with the eye tissue, may accidentally touch the tissue causing a
further tear or causing physical damage to surrounding tissue.
The laser endocoagulators used for ophthalmic surgery have
typically been rather complicated in their structure. For example,
typically the handtool of a laser endocoagulator is quite expensive
in its construction because it is made entirely from stainless
steel. Thus, the practice in the art has been to resterilize the
entire endocoagulator so that it can be reused time after time.
However, not only are such resterilization techniques time
consuming and expensive in terms of additional labor and handling,
but it also renders it more difficult to maintain the delicate
optical fiber of the endocoagulator in top condition. For example,
it is important that the end of the optical fiber be polished and
free from debris so that the laser beam will be transmitted without
interference. Any irregularity in the tip of the optical fiber may
cause a portion of the light to be absorbed, thus decreasing the
amount of the light transmitted causing the tip of the fiber to
become overheated, as well as degrading the quality of the laser
beam omitted from the tip of the fiber.
Additionally, the connectors utilized to attach the optical fiber
to the laser source have generally consisted of a number of very
carefully machined metal parts adapted to fit together with great
precision so as to accurately align the optical fiber with the
laser beam. If the laser beam is not properly aligned with the end
of the optical fiber, much of its power can be lost. Additionally,
the misdirected beam can vaporize portions of the connector, thus
destroying it or creating debris which can obscure the end of the
fiber.
Some of the connectors used in the prior art have incorporated a
series of lenses to focus the laser beam onto the end of the
optical fiber. Many prior art type connectors also incorporate a
convex, gold collar disposed about the end of the optical fiber so
as to provide an inert reflective surface for the laser beam in the
event that it is not precisely aligned with the end of the optical
fiber.
While these prior art connectors have proven effective, they are
disadvantageous for several reasons. First, such connectors are
very expensive to manufacture because of the number of parts that
must be carefully machined so as to fit together within extremely
close tolerances. While this disadvantage is partially offset by
the fact that the connectors are reusable, this creates a second
problem. The optical fiber held between the probe and the connector
is typically in need of repair or replacement after only a few
surgical operations. Because of the need for extremely precise
positioning of the optical fiber within the endocoagulator and its
connector, it has heretofore been necessary to send the entire
assembly back to the factory for repair or replacement. Since the
time required for these repairs is generally several weeks, it has
proven necessary for hospitals performing large numbers of
ophthalmic operations to have many endocoagulator assemblies in
their inventory. This requires a large capital outlay and
significant inventory cost.
Another problem associated with prior art laser endocoagulators is
the need to insure that they are absolutely sterile before reuse.
Inasmuch as the tip of the probe is inserted within the eye,
extreme care must be taken to insure that the probe is completely
sterile to prevent the introduction of bacteria.
Thus, what is needed in the art is a laser endocoagulator apparatus
which is very simple in its construction and which is economical to
manufacture so that it can be easily disposed of after a single
use, and which effectively overcomes the disadvantages of the prior
art type endocoagulators mentioned above.
OBJECTS AND BRIEF SUMMARY OF THE INVENTION
It is a primary object of the present invention to provide a laser
endocoagulator apparatus which is relatively simple in its
construction and which is inexpensive to manufacture so that it can
be utilized once and discarded.
It is a further object of this invention to provide a laser
endocoagulator apparatus which includes a simple and inexpensive
connector which insures that the optical fiber is precisely aligned
with the output of the laser source.
Another object of the present invention is to provide an
endocoagulator apparatus for use with an argon ion laser so as to
provide greater precision in the use of the laser beam.
These and other objects and features of the present invention will
become more fully apparent from the following description and
appended claims taken in conjunction with the accompanying
drawings.
In accordance with the foregoing objects, the present invention
provides a novel laser endocoagulator apparatus suitable for use in
ophthalmic surgery. The entire apparatus is inexpensive to
manufacture and thus disposable.
In the presently preferred embodiment, the laser endocoagulator
apparatus of the present invention includes an elongated handtool
constructed of plastic. The end of the handtool is slightly tapered
and a stainless steel probe projects from the end thereof. A
silicon clad optical fiber passes through the center of the
handtool and the fiber terminates at the end of the probe. A series
of circular grooves are formed on the forward portion of the
handtool to facilitate its handling. A two-piece disposable
connector is attached to the other end of the optical fiber for
attaching the fiber to a laser source. The connector includes a
cylindrical plastic body having a bore passing through the center
thereof into which the optical fiber is anchored. A small metal
plug, machined to the necessary tolerance, is positioned in the
terminal end of the plastic body for precisely aligning the tip of
the optical fiber with the output of the laser source.
BRIEF DESCRIPTION OF THE DRAWINGS
Reference is next made to the drawings, in which like parts are
designated with like numerals throughout, and in which:
FIG. 1 is a perspective view of the handtool, optical fiber and
connector forming the endocoagulator apparatus of the present
invention; and
FIG. 2 is a longitudinal cross-sectional view of the handtool and
connector taken along line 2--2 of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring first to FIG. 1, the laser endocoagulator apparatus of
the present invention is generally designated at 10. The apparatus
10 includes an elongated, generally pencil-like handtool which is
generally designated at 12, a length of optical fiber generally
designated at 14 which is connected at one end to the handtool 12,
and which is connected at the other end to a cylindrically shaped
connector generally designated at 16. The handtool is tapered to a
point at its forward end 18.
On performing ophthalmic surgery, it is of utmost importance to
exercise great care so as to insure precision and accuracy in
inserting and positioning the probe within the interior regions of
the eye. Thus, the handtool 12 is slightly tapered along its body
from the leading end 20 back to the trailing end 22. Also, the
leading end 20 of the body is provided with a plurality of annular
grooves 21 which facilitate gripping and handling of the handtool
with a greater degree of precision and accuracy. The slender,
tapered, pencil-like shape of handtool 12 is specifically designed
to meet the needs of ophthalmic surgeons so as to facilitate
handling and precision in using the instrument.
The handtool 12 is, in the preferred embodiment, constructed as an
integral piece using conventional injection molding techniques or
the like. Handtool 12 is typically made from ABS (acrylonitrile
butadiene styrene) plastic material or other similar material so as
to be economical, lending to disposability of the handtool after
its use. Also, in the preferred embodiment the handtool 12 is
constructed from a plastic material which has a generally grey,
flat, dull finish. Since ophthalmic surgeons typically must operate
in the environment of an almost totally dark operating room, it is
desirable to avoid using instruments which are light colored or
which may be highly reflective and which might thus detract from
the field of surgery.
A stainless steel, medical grade probe in the form of a thin,
elongated tube 24 is anchored to the tip 18 of handtool 12. As
hereinafter more fully described, probe 24 carries inside of it the
optical fiber through which the laser beam is transmitted.
Typically, the probe 24 is inserted into the interior regions of
the eye through a small incision.
With reference next to FIG. 2, it will be seen that the optical
fiber generally designated at 14 includes a small quartz fiber 26
through which the laser beam is optically transmitted to the
leading tip 25 of the metal probe 24. The leading end of the quartz
fiber 26 is inserted through the probe 24 to a point just slightly
beyond the tip of the probe 24. The end of the quartz fiber is then
polished to remove debris such as excess adhesive or the like which
may be attached to the tip of the quartz fiber 26 during assembly
procedures. Since the quartz fiber 26 is typically very small (on
the order of 400 microns), except for its leading end the quartz
fiber 26 is encased in a silicon sheath 28 which enhances the
optical transmission properties of fiber 26, and which also lends
structural support to the quartz fiber 26 and protects it from
being damaged. In some cases, an additional layer (not shown) of
Tefzel (TM) may be used to give further strength to the quartz
fiber 26. The silicon clad quartz fiber is commonly referred to as
a "dressed optical fiber," and is commercially available from one
of several companies. For example, in the illustrated embodiment
the dressed optical fiber is a black fiber which is advantageous
for use in the context of ophthalmic surgery because it inhibits
transmission of light except at the tip of the probe, which fiber
may be obtained from Quartz Products Company of Plainfield,
N.J.
The dressed optical fiber consisting of silicon sheath 28 and
quartz fiber 26 is further encased in a flexible plastic tube 30
which protects the portion of the fiber which leads from the
handtool 12 to the connector 16. Tubing 30 can be constructed of
polyethylene or polypropylene plastic or other suitable
material.
As shown best in FIG. 2, the optical fiber 14 is inserted through
the interior of the handtool 12 by means of an interior bore 32
which extends through the center of the handtool 12. At one end 34
the bore is diametrally enlarged for purposes of receiving the
plastic tubing 30, which is bonded or otherwise anchored to
trailing end 22 of the handtool 12. At the other end of bore 32, an
annular shoulder 36 is formed so as to reduce the diameter of the
bore. The annular shoulder 36 defines the farthest point at which
the metal probe 24 may be inserted into the tapered end 18 of
handtool 12. The inside diameter of the metal probe 24 and the
reduced diameter defined by annular shoulder 36 correspond in size
to the outside diameter of the sheath 28 encasing quartz fiber 26,
whereas the inside diameter of the bore 32 is sized to accept the
outside diameter of the silicon sheath 28 which is used for
purposes of encasing the quartz fiber 26. The optical fiber may be
suitably bonded or otherwise secured inside the bore 32 and metal
probe 24.
As schematically illustrated in FIG. 2, the laser endocoagulator of
the present invention is adapted to be connected by means of the
connector 16 to a conventional laser source, which, in the
preferred embodiment, may be an argon ion type laser manufactured
by American Laser Corporation in Salt Lake City, Utah. Argon lasers
produce a visible blue-green light having a wavelength in the 488
to 514 nanometer range. This light is easily transmitted through
clear aqueous tissue such as the cornea, lens, and vitreous humor
of the eye. On the other hand, certain tissue pigments such as
melanin and hemoglobin absorb the light omitted by an argon laser
very effectively. Thus, an argon laser is very effective, even more
so than a xenon laser, when used for purposes of endocoagulation in
ophthalmic surgery.
The connector 16 is configurated as a male fitting which is
designed to be received by a corresponding female socket (not
shown) provided in the argon laser. Connector 16 includes a
cylindrical body 38 which is constructed of a rigid plastic
material so as to be inexpensive and easily manufactured using
conventional molding technology. The exterior surface of connector
16 is provided with a plurality of annular grooves 42 which permit
the connector 16 to be securely grasped when inserting or removing
the connector 16 from the corresponding socket of the laser.
As illustrated in FIG. 2, the body 38 of connector 16 has an
enlarged bore 46 formed in one end thereof which in turn
communicates with a diametrally reduced bore 44 which extends
through the remaining length of the body 38. Bore 44 is adapted to
receive the protective tubing 30 which surrounds the optical
fiber.
As mentioned above, it is essential that the quartz fiber 26 be
precisely aligned with the laser beam which is output from the
laser source. Because it is difficult to manufacture plastic
connectors within the necessary degree of tolerance required to
assure the needed alignment, the current practice in the art is to
construct the connectors entirely out of high precision, machined
steel components which, in some cases, go so far as to include
special lenses or reflecting apparatus to insure focusing of the
laser beam onto the exposed tip of the quartz fiber. The apparatus
of the present invention seeks to overcome the disadvantages which
are inherent in the use of these kinds of expensive and complicated
connecting apparatus by providing a connector which is simple and
inexpensive in its overall construction, but which does not
sacrifice the needed precision in terms of alignment.
As shown in FIG. 2, a small metal plug 40 is joined to the plastic
body 38 of the connector. Plug 40 is made from stainless steel so
that it can be machined within extremely close tolerances, thus
insuring precise alignment of the optical fiber positioned in the
plug with the laser beam output by the laser.
Obviously, materials other than plastic and metal could be used for
the body 38 and plug 40 of connector 16. For example, it may be
possible to form the plug 40 out of some types of plastic where the
particular type of plastic can be machined or otherwise formed
within the necessary tolerance to insure proper alignmment, in
which case the body 38 and plug 40 could be formed either as an
integral, one-piece connector, or in two pieces as illustrated. The
dominant considerations in choosing the particular materials for
body 38 and plug 40 are to select a material, like plastic, which
can be used for the body portion so as to minimize expense, thus
lending to disposability, and to select a material, like stainless
steel, which can be used for the smaller plug portion and which can
be machined with great precision to insure proper alignment of the
optical fiber with the laser beam. Thus, use of the terms "plastic"
and "metal" is not intended to be a limitation on the scope of the
invention, but is instead intended to be representative of the
foregoing design considerations.
Plug 40 includes an annular extension 48 which is adapted to be
received by the diametrally enlarged bore 46 formed in the end of
the plastic body 38. The tip of plug 40 is chamfered as at 56 to
facilitate insertion of the plug 40 into the corresponding socket
of the laser. A through bore 50 is formed through the center of the
plug 40 along a portion of its length. The inside diameter of bore
50 corresponds to the outside diameter of the silicon sheath 28
which surrounds the quartz fiber 26. The silicon sheath 28 is
stripped from the end 58 of quartz fiber 26, which then projects
through the diametrally reduced bore 52 located in the end portion
of plug 40.
The tip of plug 40 also includes a conical recess 54 into which the
tip 58 the of quartz fiber 26 extends a short distance so as to be
entirely exposed to the laser beam output by the laser source. The
tip 58 of the optical fiber is preferably recessed slightly within
cavity 54 so that it cannot be damaged during storage or handling.
The length of plug 40 is designed such that the end 60 of the
plastic body 38 will abut against the female socket into which the
plug 40 is inserted.
In summary, from the foregoing description and drawings it will be
appreciated that the endocoagulator apparatus of the present
invention may be efficiently and economically constructed largely
using plastic materials which may be easily manufactured using
conventional molding technology and thus lending to disposability
of the entire apparatus after a single use. The laser
endocoagulator of this invention advantageously provides for easier
handling and greater precision in using the laser beam for purposes
of ophthalmic surgery.
Although the present invention has been described with reference to
its presently preferred embodiment, the invention may be embodied
in other specific forms without departing from the spirit or
essential characteristics thereof. The described embodiment is to
be considered in all respects only as illustrative and not
restrictive, and the scope of the invention is, therefore,
indicated by the appended claims rather than by the foregoing
description. All modifications or changes which come within the
meaning and range of equivalency of the claims are to be embraced
within their scope.
* * * * *